1. Field of the Invention
The present invention relates generally to semiconductor laser devices, and more particularly, to a semiconductor laser device comprising an active layer having a quantum well structure and an optical recording medium drive using the same.
2. Description of the Background Art
An AlGaInP system semiconductor laser device has been actively studied and developed as a semiconductor laser device having a lasing wavelength in a red band. The AlGaInP system semiconductor laser device can carry out lasing in a band of 630 to 680 nm, and the wavelength band is high in spectral luminous efficacy. Therefore, the semiconductor laser device is used for a laser pointer, a line marker, and the like. The semiconductor laser device has a shorter lasing wavelength than an AlGaAs system semiconductor laser device, whereby it is expected as a light source for high-density recording, for example, and is scheduled to be employed as a light source of a digital video disc (DVD) currently proposed.
In such a semiconductor laser device, the inventors of the present application have found that the maximum light output power can be improved to approximately 40 mW by employing a strain compensation type multi quantum well structure for an active layer.
When the semiconductor laser device is used as a light source for a reloadable optical recording medium, however, it is desired to lengthen the life of the semiconductor laser device while increasing the maximum light output power.